The prior art includes technology for spark ignition engine that achieved air management via electronic controls. Air flow management devices for engine applications have historically used brush type permanent magnet motors and pulse width modulation speed control. Brush type permanent magnet motors do not maintain a sufficient reliability because of a relatively short life expectancy. Therefore a need exists for the use of brushless motors.
Due to the low life expectancy of brush type DC motors, some original equipment (OE) companies have developed the throttle valve further to incorporate brushless direct current (BLDC) motor technology. BLDC motor technology is employed because of high vibration/load, high torque to package ratio, high speed, and angular accuracy. However, the primary application for such valves is to meter air flow of air induction systems on the inlet side of naturally or forced induction engine applications. Therefore, a need exists to use a robust brushless design for use in a variety of applications requiring a long lifespan.
In the prior art, high-level control is generally provided by the engine control unit (ECU). Commands from the ECU to the motor are determined by application-specific operating strategies based on multiple engine operating parameters including load and speed. An air valve shaft position sensor is required in these applications to provide feedback for the ECU.
The throttle position sensor has typically used a contact wiper in the prior art. This device is also subject to reliability issues because of a relatively short life expectancy. Therefore, a need exists for a contact-less sensor for improved reliability and accuracy.
Moreover, the prior art includes complex and cumbersome designs for air valves and sensors that are difficult to fit into applications because of size, weight, and other considerations. Therefore, a need exists for a compact, efficient packaged design that allows for use in a variety of applications.